Method and system for moving an articulated instrument back towards an entry guide while automatically reconfiguring the articulated instrument for retraction into the entry guide

ABSTRACT

A medical robotic system includes articulated instruments extending out of a distal end of an entry guide. Prior to pivoting the entry guide to re-orient it and the instruments, the instruments are moved in tandem back towards the entry guide. Haptic cues and velocity limits are provided to assist the operator in the retraction of the instruments. After retraction, the entry guide may then be pivoted without concern that the instruments will harm patient anatomy. The movement of the instruments in tandem back towards the entry guide may also occur through coupled control modes while the entry guide is held in a fixed position and orientation.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation to U.S. application Ser. No.13/294,403, filed Nov. 11, 2011, which is a continuation-in-part to U.S.application Ser. No. 12/780,071, filed May 14, 2010, now U.S. Pat. No.8,620,473, which is a continuation-in-part to U.S. application Ser. No.11/762,200, filed Jun. 13, 2007, now U.S. Pat. No. 7,725,214, each ofwhich is incorporated herein by reference.

This application is also a continuation-in-part to U.S. application Ser.No. 12/489,566, filed Nov. 5, 2009, now U.S. Pat. No. 9,089,256, whichis incorporated herein by reference.

This application is also a continuation-in-part to U.S. application Ser.No. 12/613,328, filed Nov. 5, 2009, now U.S. Pat. No. 9,084,623, whichis a continuation-in-part to U.S. application Ser. No. 12/541,913, filedAug. 15, 2009, now U.S. Pat. No. 8,903,546, each of which isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention generally relates to medical robotic systems andin particular, to a method and system for moving a plurality ofarticulated instruments in tandem back towards an entry guide out ofwhich the plurality of articulated instruments extend.

BACKGROUND OF THE INVENTION

Medical robotic systems such as teleoperative systems used in performingminimally invasive surgical procedures offer many benefits overtraditional open surgery techniques, including less pain, shorterhospital stays, quicker return to normal activities, minimal scarring,reduced recovery time, and less injury to tissue. Consequently, demandfor such medical robotic systems is strong and growing.

One example of such a medical robotic system is the DA VINCI® SurgicalSystem from Intuitive Surgical, Inc., of Sunnyvale, Calif., which is aminimally invasive robotic surgical system. The DA VINCI® SurgicalSystem has a number of robotic arms that move attached medical devices,such as an image capturing device and Intuitive Surgical's proprietaryENDOWRIST® articulated surgical instruments, in response to movement ofinput devices operated by a Surgeon viewing images captured by the imagecapturing device of a surgical site. Each of the medical devices isinserted through its own minimally invasive incision into the Patientand positioned to perform a medical procedure at the surgical site. Theincisions are placed about the Patient's body so that the surgicalinstruments may be used to cooperatively perform the medical procedureand the image capturing device may view it.

To perform certain medical procedures, however, it may be advantageousto use a single aperture, such as a minimally invasive incision or anatural body orifice, to enter a Patient to perform a medical procedure.For example, an entry guide (also referred to as a “guide tube”) mayfirst be inserted, positioned, and held in place in the entry aperture.Instruments such as an articulated camera and a plurality of articulatedsurgical tools, which are used to perform the medical procedure, maythen be inserted into a proximal end of the entry guide so as to extendout of its distal end. Thus, the entry guide provides a single entryaperture for multiple instruments while keeping the instruments bundledtogether as it guides them toward the work site.

U.S. 2009/0326318 A1 describes visual cues that aid an operator inrepositioning the orientation of an entry guide so that the ranges ofmotion of articulated instruments extending out of its distal end may beoptimized. U.S. 2011/0040305 A1 describes controller assistedreconfiguration of an articulated instrument during its movement intoand out of an entry guide. U.S. 2011/0201883 A1 describes an entry guidefor multiple instruments in a single port surgical system. U.S.2008/0071288 A1 describes minimally invasive surgery guide tubes,articulated instruments extendable out of the guide tubes, andcontrollers for controlling movements of the guide tubes andinstruments.

In addition to optimizing the ranges of motion of the articulatedinstruments, it may be necessary to change the orientation of the entryguide and consequently articulated instruments disposed therein so thatone or more of the articulated instruments may reach or otherwise accessa location within a Patient where a medical procedure is to beperformed. When changing the orientation of the entry guide, however,care should be taken to ensure that the articulated instrumentsextending out of its distal end do not strike and harm surroundingtissue or other anatomical structures of the Patient. Also, haptic cuesmay be provided to assist a Surgeon during the entry guidere-orientation process.

OBJECTS AND SUMMARY

Accordingly, one object of one or more aspects of the present inventionis a medical robotic system and method implemented therein thatfacilitates changing the orientation of an entry guide, through whicharticulated instruments are extendable, in a manner that avoids harminga Patient.

Another object of one or more aspects of the present invention is amedical robotic system and method implemented therein that facilitateschanging the orientation of an entry guide, through which articulatedinstruments are extendable, in a quick and efficient manner thatminimizes the steps to be performed by an operator of the medicalrobotic system.

Still another object of one or more aspects of the present invention isa medical robotic system and method implemented therein that facilitatesoperator controlled retraction of one or more articulated instrumentsinto an entry guide as part of the process of re-orienting the entryguide or in other applications in which such controlled retraction isuseful.

Yet another object of one or more aspects of the present invention is amedical robotic system and method implemented therein for retracting aplurality of articulated instruments in tandem back towards an entryguide out of which the plurality of articulated instruments extend.

These and additional objects are accomplished by the various aspects ofthe present invention, wherein briefly stated, one aspect is a methodfor moving a plurality of articulated instruments in tandem back towardsan entry guide, the method comprising: causing the plurality ofarticulated instruments to assume retraction configurations only inresponse to one or more commands to move the plurality of articulatedinstruments in tandem back towards the entry guide by a distance greaterthan a retraction-on distance from an initial position.

Another aspect is a method for re-orienting an entry guide having aplurality of articulated instruments extending out of the entry guide,the method comprising: generating a first command to move the entryguide translationally along its longitudinal axis in a retractiondirection by a distance exceeding a locking distance from an initialposition; causing joints used for pivoting the entry guide to be lockedin place in response to the first command; generating second commands tomove the entry guide translationally along its longitudinal axis in theretraction direction by distances greater than a retraction-on distancefrom the initial position, wherein the retraction-on distance is greaterthan the locking distance; causing the plurality of articulatedinstruments to assume retraction configurations and be retracted intandem back towards the entry guide in response to the second commands;causing the joints used for pivoting the entry guide to be unlockedafter the plurality of articulated instruments has been retracted backtowards the entry guide by a distance that allows pivoting of the entryguide without any of the plurality of articulated instruments harmingany patient anatomy; generating third commands to pivot the entry guideto a different orientation; and causing the joints used for pivoting theentry guide to pivot the entry guide in response to the third commands.

Another aspect is a robotic system comprising: at least one inputdevice; an entry guide; a plurality of articulated instruments extendingout of a distal end of the entry guide; a plurality of instrumentmanipulators for manipulating corresponding ones of the plurality ofarticulated instruments; and a processor adapted to: command theplurality of instrument manipulators to manipulate the plurality ofarticulated instruments so as to assume retraction configurations inresponse to one or more commands received from the at least one inputdevice to move the plurality of articulated instruments in tandem backtowards the entry guide by a distance greater than a retraction-ondistance from an initial position.

Additional objects, features and advantages of the various aspects ofthe present invention will become apparent from the followingdescription of its preferred embodiment, which description should betaken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic view of a medical robotic systemutilizing aspects of the present invention.

FIGS. 2 and 3 respectively illustrate alternative embodiments of aPatient side support system useful in a medical robotic system utilizingaspects of the present invention.

FIG. 4 illustrates reference frames and degrees-of-freedom associatedwith manipulation of an entry guide in a medical robotic systemutilizing aspects of the present invention.

FIG. 5 illustrates a block diagram of components of an entry guidemanipulator for manipulating an entry guide in a medical robotic systemutilizing aspects of the present invention.

FIG. 6 illustrates a front view of a Surgeon console useful in a medicalrobotic system utilizing aspects of the present invention.

FIG. 7 illustrates a perspective view of a distal end of an entry guidewith articulated instruments extending out of it in a medical roboticsystem utilizing aspects of the present invention.

FIG. 8 illustrates a cross-sectional view of an entry guide useful in amedical robotic system utilizing aspects of the present invention.

FIG. 9 illustrates a perspective view of a proximal segment of anarticulated instrument useful in a medical robotic system utilizingaspects of the present invention.

FIG. 10 illustrates a perspective view of a segment of an actuatorassembly of an instrument manipulator that mates with and actuates anarticulated instrument useful in a medical robotic system utilizingaspects of the present invention.

FIG. 11 illustrates a first perspective view of articulated instrumentassemblies mounted on a platform coupled to a robotic arm assembly in amedical robotic system utilizing aspects of the present invention.

FIG. 12 illustrates a second perspective view of articulated instrumentsassemblies mounted on a platform coupled to a robotic arm assembly in amedical robotic system utilizing aspects of the present invention.

FIG. 13 illustrates a block diagram of components for controlling andselectively associating controllable devices with input devices of amedical robotic system utilizing aspects of the present invention.

FIG. 14 illustrates a side view of a pivoting entry guide with anarticulated instrument extending out of its distal end in a medicalrobotic system utilizing aspects of the present invention.

FIG. 15 illustrates a side view of a pivoting entry guide with anarticulated instrument retracted into the entry guide in a medicalrobotic system utilizing aspects of the present invention.

FIG. 16 illustrates a flow diagram of a method utilizing aspects of thepresent invention for re-orienting an entry guide with at least onearticulated instrument disposed in it.

FIG. 17 illustrates a block diagram of components of a medical roboticsystem in an entry guide mode with coupled control of articulatedinstruments utilizing aspects of the present invention.

FIGS. 18A-18C illustrate top views of an entry guide in various stagesof retracting articulated instruments into the entry guide in a medicalrobotic system utilizing aspects of the present invention.

FIG. 19 illustrates a flow diagram of a method utilizing aspects of thepresent invention for moving a plurality of articulated instruments intandem back towards an entry guide.

FIG. 20 illustrates a force versus commanded position changerelationship usable in a method utilizing aspects of the presentinvention for moving at least one articulated instrument back towards anentry guide.

FIG. 21 illustrates a velocity versus commanded position changerelationship usable in a method utilizing aspects of the presentinvention for moving at least one articulated instrument back towards anentry guide.

FIG. 22 illustrates a block diagram of components of a medical roboticsystem in a camera mode with coupled control of articulated instrumentsutilizing aspects of the present invention.

FIG. 23 illustrates a block diagram of components of a medical roboticsystem in an instrument following mode with coupled control ofarticulated instruments utilizing aspects of the present invention.

FIG. 24 illustrates a flow diagram of an alternative method utilizingaspects of the present invention for moving a plurality of articulatedinstruments in tandem back towards an entry guide.

FIG. 25 illustrates a force versus commanded position changerelationship usable in the alternative method utilizing aspects of thepresent invention for moving at least one articulated instrument backtowards an entry guide.

FIG. 26 illustrates a velocity versus commanded position changerelationship usable in the alternative method utilizing aspects of thepresent invention for retracting at least one articulated instrumentback towards an entry guide.

DETAILED DESCRIPTION

FIG. 1 illustrates, as an example, a schematic view of a medical roboticsystem 2100 in which instruments are inserted in a Patient through asingle entry aperture through an entry guide. The system's generalarchitecture is similar to the architecture of other such systems suchas Intuitive Surgical, Inc.'s DA VINCI® Surgical System and the ZEUS®Surgical System. The three main components are a Surgeon console 2102, aPatient side support system 2104, and a video system 2106, allinterconnected by wired or wireless connections 2108 as shown.

The Patient side support system 2104 includes a floor-mounted structure2110, or alternately a ceiling mounted structure 2112 as shown by thealternate lines. It also includes a set-up arm assembly 2114, an entryguide manipulator (EGM) 2116, a platform 2118, an entry guide (EG) 2000,and one or more instrument assemblies 2500. The structure 2110 may bemovable or fixed (e.g., to the floor, ceiling, or other equipment suchas an operating table). In one embodiment, the set-up arm assembly 2114includes two illustrative passive rotational setup joints 2114 a, 2114b, which allow manual positioning of the coupled links when their brakesare released. A passive prismatic setup joint (not shown) between thearm assembly 2114 and the structure 2110 may be used to allow for largevertical adjustments.

The entry guide 2000 is coupled to the platform 2118, which in turn, iscoupled to the entry guide manipulator 2116 so that the entry guidemanipulator 2116 may pivot the platform 2118, which in turn, causes theentry guide 2000 to pivot about a Remote Center (RC) point. As shown ina perspective view of the entry guide 2000 in FIG. 4, the entry guide2000 is generally cylindrical in shape and has a longitudinal axis X′running centrally along its length. The RC point serves as an origin forboth a fixed reference frame having X, Y and Z axes as shown and anentry guide reference frame having X′, Y′ and Z′ axes as shown. When thesystem 2100 is in an “entry guide” mode, the entry guide manipulator2116 pivots the entry guide 2000, in response to movement of one or moreassociated input devices commanding such pivoting, about the Z axis(which remains fixed in space) at the RC point in yaw ψ. In addition,the entry guide manipulator 2116 pivots the entry guide 2000, inresponse to movement of the one or more input devices commanding suchpivoting, about the Y′ axis (which is orthogonal to the longitudinalaxis X′ of the entry guide 2000) in pitch θ; rotates the entry guide2000, in response to movement of the one or more input devicescommanding such rotation, about its longitudinal axis X′ in roll Φ; andoptionally, linearly moving the entry guide 2000, in response tomovement of the one or more input devices commanding such movement,along its longitudinal axis X′ in insertion/retraction or in/out “I/O”directions. Note that unlike the Z-axis which is fixed in space, the X′and Y′ axes move with the entry guide 2000.

The entry guide manipulator 2116 includes illustrative active (i.e.,actuatable) yaw joint 2116 a and active pitch joint 2116 b. Joints 2116c and 2116 d act as a parallel mechanism so that the entry guide 2000being held by the platform 2118 may pivot in yaw and pitch about the RCpoint which is positioned at an entry port 2120, such as an umbilicus ofPatient 2122, prior to the performance of a medical procedure using theset-up arm assembly 2114. In one embodiment, an active prismatic joint2124 may be used to insert and retract the entry guide 2000. One or moreinstrument assemblies 2500 such as assemblies for surgical instrumentsand an endoscopic imaging system are independently mounted to platform2118 so as to be disposed within and extendable through the entry guide2000.

Thus, the set-up arm assembly 2114 is used to position the entry guide2000 in the entry port 2120 of the Patient 2122 when the Patient 2122 isplaced in various positions on movable table 2126. After set-up of theentry guide 2000, instrument assemblies 2500 are mounted on the platform2118 so that their articulated instruments extend into the entry guide2000. The entry guide manipulator 2116 may then be used to pivot theentry guide 2000 and the articulated instruments disposed therein aboutthe RC point in pitch and yaw. Rotation of the entry guide 2000 and/orinsertion/retraction of the entry guide 2000 by the entry guidemanipulator 2116 do not necessarily result in corresponding movement ofthe articulated instruments disposed therein, however.

As shown in FIG. 5, the entry guide manipulator (EGM) 2116 has fouractuators 501-504 for actuating the four degrees-of-freedom movement ofthe entry guide 2000 (i.e., yaw ψ, pitch θ, roll Φ, and in/out I/O) andfour corresponding assemblies 511-514 to implement them. The EGM yawassembly 511 includes the yaw rotary joint 2116 a and one or more linksthat couple it through other parts of the entry guide manipulator 2116to the platform 2118 so that when the EGM yaw actuator 501 (e.g., amotor) actuates (e.g., rotates) the yaw rotary joint, the entry guide2000 is rotated about the fixed Z-axis at the RC point in yaw ψ. The EGMpitch assembly 512 includes the pitch rotary joint 2116 b and one ormore links that couple it through other parts of the entry guidemanipulator 2116 to the platform 2118 so that when the EGM pitchactuator 502 (e.g., a motor) actuates (e.g., rotates) the pitch rotaryjoint, the entry guide 2000 is rotated about the Y′-axis at the RC pointin pitch θ. The EGM roll assembly 513 includes a gear assembly thatcouples the entry guide 2000 to an EGM roll actuator 503 so that whenthe EGM roll actuator 503 (e.g., a motor) actuates (e.g., its rotorrotates), the entry guide 2000 rotates about its longitudinal axis X′ inresponse. In one embodiment, the EGM I/O assembly 514 includes aprismatic joint that is coupled to the EGM I/O actuator 504 so that whenthe EGM I/O actuator 504 (e.g., a motor) actuates (e.g., its rotorrotates), the rotary action is transferred into a linear displacement ofthe entry guide 2000 along its longitudinal axis X′. In anotherembodiment, rather than moving the entry guide 2000 in theinsertion/retraction direction, all articulated instruments disposed inthe entry guide 2000 are moved instead in the insertion/retractiondirection in response to an EG I/O command.

FIGS. 2 and 3 illustrate, as examples, alternative embodiments of thePatient side support system 2104. Support 2150 is fixed (e.g., floor orceiling mounted). Link 2152 is coupled to support 2150 at passiverotational setup joint 2154. As shown, joint 2154's rotational axis isaligned with RC point 2156, which is generally the position at which anentry guide (not shown) enters the Patient (e.g., at the umbilicus forabdominal surgery). Link 2158 is coupled to link 2152 at rotationaljoint 2160. Link 2162 is coupled to link 2158 at rotational joint 2164.Link 2166 is coupled to link 2162 at rotational joint 2168. The entryguide is mounted to slide through the end 2166 a of link 2166. Platform2170 is supported and coupled to link 2166 by a prismatic joint 2172 anda rotational joint 2174. Prismatic joint 2172 inserts and retracts theentry guide as it slides along link 2166. Joint 2174 includes a bearingassembly that holds a “C” shaped ring cantilever. As the “C” ring slidesthrough the bearing it rotates around a center point inside the “C”,thereby rolling the entry guide. The opening in the “C” allows entryguides to be mounted or exchanged without moving overlying manipulators.Platform 2170 supports multiple instrument manipulators 2176 forsurgical instruments and an imaging system, as described below.

These illustrative robotic arm assemblies (i.e., set-up arm assembliesand entry guide manipulators) are used, for example, for instrumentassemblies that include a rigid entry guide and are operated to movewith reference to a Remote Center (RC) point. Certain setup and activejoints in the robotic arm assemblies may be omitted if motion around aremote center is not required. It should be understood that set-up andmanipulator arms may include various combinations of links, passive, andactive joints (redundant DOFs may be provided) to achieve a necessaryrange of poses for surgery.

Referring again to FIG. 1, the video system 2106 performs imageprocessing functions for, e.g., captured endoscopic imaging data of thesurgical site and/or preoperative or real time image data from otherimaging systems external to the Patient. Video system 2106 outputsprocessed image data (e.g., images of the surgical site, as well asrelevant control and Patient information) to the Surgeon at the Surgeonconsole 2102. In some aspects the processed image data is output to anoptional external monitor visible to other operating room personnel orto one or more locations remote from the operating room (e.g., a Surgeonat another location may monitor the video; live feed video may be usedfor training; etc.).

FIG. 6 illustrates, as an example, a front view of the Surgeon console2102 which a Surgeon or other user operates for controlling movement ofthe entry guide and articulated instruments of the system 2100. TheSurgeon console 2102 has left and right input devices 41, 42 which theuser may grasp respectively with his/her left and right hands tomanipulate associated devices, such as the entry guide and articulatedinstruments, in preferably six degrees-of-freedom. Foot pedals 44 withtoe and heel controls are provided on the Surgeon console 2102 so theuser may control movement and/or actuation of devices associated withthe foot pedals. A processor 43 is provided in the Surgeon console 2102for control and other purposes. Although shown as a single processorlocated in the base of the Surgeon console 2102, the processor 43 may beimplemented as multiple cooperative processors distributed in theSurgeon console 2102 as well as other parts of the medical roboticsystem 2100. A stereo viewer 45 is also provided in the Surgeon console2102 so that the user may view the work site in stereo vision fromimages captured by a stereoscopic camera of an articulated camerainstrument. Left and right eyepieces, 46 and 47, are provided in thestereo viewer 45 so that the user may view left and right 2-D displayscreens inside the viewer 45 respectively with the user's left and righteyes.

The Surgeon console 2102 is usually located in the same room as thePatient 2122 so that the Surgeon may directly monitor the procedure, isphysically available if necessary, and is able to speak to anyassistants in the operating room directly rather than over the telephoneor other communication medium. However, it will be understood that theSurgeon can also be located in a different room, a completely differentbuilding, or other remote location from the Patient allowing for remotesurgical procedures.

As shown in FIG. 7, the entry guide 2000 has articulated instrumentssuch as articulated surgical tool instruments 231, 241 and anarticulated stereo camera instrument 211 (or other image capturingdevice instrument) extending out of its distal end. The camerainstrument 211 has a pair of stereo image capturing devices 311, 312 anda fiber optic cable 313 (coupled at its proximal end to a light source)housed in its tip. The surgical tools 231, 241 have end effectors 331,341. Although only two tools 231, 241 are shown, the entry guide 2000may guide additional tools as required for performing a medicalprocedure at a work site in the Patient. For example, as shown in FIG.8, a passage 351 is available for extending another articulated surgicaltool through the entry guide 2000 and out through its distal end.Passages 431, 441, and 321 are respectively used by the articulatedsurgical tool instruments 231, 241, and articulated camera instrument211. Each of the surgical tools 231, 241 is associated with one of theinput devices 41, 42 in a tool following mode. The Surgeon performs amedical procedure by manipulating the input devices 41, 42 so that thecontroller 43 causes corresponding movement of their respectivelyassociated surgical tools 231, 241 while the Surgeon views the work sitein 3-D on the console stereo viewer 45 as images of the work site arebeing captured by the articulated camera instrument 211.

Preferably, input devices 41, 42 will be provided with at least the samedegrees of freedom as their associated tools 231, 241 to provide theSurgeon with telepresence, or the perception that the input devices 41,42 are integral with the tools 231, 241 so that the Surgeon has a strongsense of directly controlling the tools 231, 241. To this end, thestereo viewer 45 is also positioned near the Surgeon's hands as shown sothat it will display a projected image that is oriented so that theSurgeon feels that he or she is actually looking directly down onto thework site and images of the tools 231, 241 appear to be locatedsubstantially where the Surgeon's hands are located.

In addition, the real-time image on the stereo viewer 45 is preferablyprojected into a perspective image such that the Surgeon can manipulatethe end effectors 331, 341 of the tools 231, 241 through theircorresponding input devices 41, 42 as if viewing the work site insubstantially true presence. By true presence, it is meant that thepresentation of an image is a true perspective image simulating theviewpoint of an operator that is physically manipulating the endeffectors 331, 341. Thus, the processor 43 transforms the coordinates ofthe end effectors 331, 341 to a perceived position so that theperspective image being shown on the stereo viewer 45 is the image thatthe Surgeon would see if the Surgeon was located directly behind the endeffectors 331, 341.

The processor 43 performs various functions in the system 2100. Oneimportant function that it performs is to translate and transfer themechanical motion of input devices 41, 42 through control signals overcommunication means 2108 to actuate actuators in their associatedmanipulators so that the Surgeon can effectively manipulate devices,such as the tool instruments 231, 241, camera instrument 211, and entryguide 2000. Another function is to perform various methods and implementvarious controllers and coupling logic described herein.

Although described as a processor, it is to be appreciated that theprocessor 43 may be implemented by any combination of hardware, softwareand firmware. Also, its functions as described herein may be performedby one unit or divided up among different components, each of which maybe implemented in turn by any combination of hardware, software andfirmware. Further, although being shown as part of or being physicallyadjacent to the console 2102, the processor 43 may also comprise anumber of subunits distributed throughout the system.

For additional details on the construction and operation of variousaspects of a medical robotic system such as described herein, see, e.g.,U.S. Pat. No. 6,493,608 “Aspects of a Control System of a MinimallyInvasive Surgical Apparatus”; U.S. Pat. No. 6,671,581 “Camera ReferencedControl in a Minimally Invasive Surgical Apparatus”; and U.S.2008/0071288 A1 “Minimally Invasive Surgery Guide Tube”; each of whichis incorporated herein by reference.

Mounting of the instrument assemblies 2500 onto the platform 2118 withtheir working ends inserted into the entry guide 2000 is now describedin reference to FIGS. 9-12. As shown in FIG. 9, articulated instrument2402 includes a transmission mechanism 2404 coupled to the proximal endof an instrument body tube 2406. Components at body tube 2406's distalend 2408 are omitted for clarity and may include actuatable joints andworking ends as shown in FIG. 7. In the illustrative embodiment shown,transmission mechanism 2404 includes six interface disks 2410. Each ofthe disks 2410 may be associated with a Degree-of-Freedom (DOF) for thearticulated instrument 2402. For instance, one disk may be associatedwith instrument body roll DOF, and a second disk may be associated withend effector grip DOF. As shown, in one instance the disks are arrangedin a hexagonal lattice for compactness—in this case six disks in atriangular shape. Other lattice patterns or more arbitrary arrangementsmay be used. Mechanical components (e.g., gears, levers, gimbals,cables, etc.) inside transmission mechanism 2404 transmit roll torqueson disks 2410 to e.g., body tube 2406 (for roll) and to componentscoupled to distal end mechanisms. Cables and/or cable and hypotubecombinations that control distal end DOFs run through body tube 2406. Inone instance the body tube is approximately 7 mm in diameter, and inanother instance it is approximately 5 mm in diameter. Raised pins 2412,spaced eccentrically, provide proper disk 2410 orientation when matedwith an associated actuator disk. One or more electronic interfaceconnectors 2414 provide an electronic interface between instrument 2402and its associated actuator mechanism. The electronic interface may alsoinclude power for, e.g., an electrocautery end effector. Alternately,such a power connection may be positioned elsewhere on instrument 2402(e.g., on transmission mechanism 2404's housing). Other connectors for,e.g., optical fiber lasers, optical fiber distal bend or force sensors,irrigation, suction, etc. may be included. As shown, transmissionmechanism 2404's housing is roughly wedge or pie-shaped to allow it tobe closely positioned to similar housings, as illustrated below.

FIG. 10 is a perspective view of a portion of an actuator assembly 2420(also referred to herein as an instrument “manipulator”) that mates withand actuates components in surgical instrument 2402. Actuator disks 2422are arranged to mate with interface disks 2410. Holes 2424 in disks 2422are aligned to receive pins 2412 in only a single 360-degreeorientation. Each disk 2422 is turned by an associated rotatingservomotor actuator 2426, which receives servocontrol inputs from itsrespective controller as described below. A roughly wedge-shapedmounting bracket 2428, shaped to correspond to instrument 2402'stransmission mechanism housing, supports the disks 2422, servomotoractuators 2426, and an electronic interface 2430 that mates withinstrument 2402's interface connectors 2414. In one instance instrument2402 is held against actuator assembly 2420 by spring clips (not shown)to allow easy removal. As shown in FIG. 10, a portion 2432 of actuatorassembly housing 2428 is truncated to allow instrument body tube 2406 topass by. Alternatively, a hole may be placed in the actuator assembly toallow the body tube to pass through.

FIG. 11 is a diagrammatic perspective view that illustrates aspects ofmounting minimally invasive surgical instruments and their associatedactuator assemblies at the end of a setup/manipulator arm. As shown inFIG. 11, surgical instrument 2502 a is mounted on actuator assembly2504, so that the transmission mechanism mates with the actuatorassembly as described above. Instrument 2502 a's body tube 2506 extendspast actuator assembly 2504 and enters a port in rigid entry guide 2508.As depicted, body tube 2506, although substantially rigid, is bentslightly between the transmission mechanism housing and the entry guide.This bending allows the instrument body tube bores in the entry guide tobe spaced closer than the size of their transmission mechanisms wouldotherwise allow. Since the bend angle in the rigid instrument body tubeis less than the bend angle for a flexible (e.g., flaccid) instrumentbody, cables can be stiffer than in a flexible body. High cablestiffness is important because of the number of distal DOFs beingcontrolled in the instrument. Also, the rigid instrument body is easierto insert into an entry guide than a flexible body. In one embodimentthe bending is resilient so that the body tube assumes its straightshape when the instrument is withdrawn from the entry guide (the bodytube may be formed with a permanent bend, which would prevent instrumentbody roll). Actuator assembly 2504 is mounted to a linear actuator 2510(e.g. a servocontrolled lead screw and nut or a ball screw and nutassembly) that controls body tube 2506's insertion within entry guide2508. The second instrument 2502 b is mounted with similar mechanisms asshown. In addition, an imaging system (not shown) may be similarlymounted.

FIG. 11 further shows that entry guide 2508 is removably mounted tosupport platform 2512. This mounting may be, for example, similar to themounting used to hold a cannula on a DA VINCI® Surgical Systemmanipulator arm. Removable and replaceable entry guides allow differententry guides that are designed for use with different procedures to beused with the same telemanipulative system (e.g., entry guides withdifferent cross-sectional shapes or various numbers and shapes ofworking and auxiliary channels). In turn, actuator platform 2512 ismounted to robot manipulator arm 2514 (e.g., 4 DOF) using one or moreadditional actuator mechanisms (e.g., for pitch, yaw, roll, insertion).In turn, manipulator arm 2514 may be mounted to a passive setup arm, asdescribed above with reference to the entry guide manipulator 2116 ofFIG. 1.

FIG. 12 is a diagrammatic perspective view that illustrates aspectsshown in FIG. 11 from a different angle and with reference to a Patient.In FIG. 12, arm 2514 and platform 2512 are positioned so that entryguide 2508 enters the Patient's abdomen at the umbilicus. This entry isillustrative of various natural orifice and incision entries, includingpercutaneous and transluminal (e.g., transgastric, transcolonic,transrectal, transvaginal, transrectouterine (Douglas pouch), etc.)incisions. FIG. 12 also illustrates how the linear actuators for eachinstrument/imaging system operate independently by showing imagingsystem 2518 inserted and instruments 2502 a, 2502 b withdrawn. It can beseen that in some instances the manipulator arm 2514 moves to rotate orpivot entry guide 2508 around a Remote Center (RC) 2520 at the entryport into a Patient. If intermediate tissue restricts movement around aremote center, however, the arm can maintain entry guide 2508 inposition.

FIG. 13 illustrates, as an example, a block diagram of components usedfor controlling and selectively associating articulated instruments onthe Patient side support system 2104 to operator manipulated inputdevices 41, 42 of the Surgeon console 2102. Various surgical tools suchas graspers, cutters, and needles may be used to perform a medicalprocedure at a work site within the Patient. In this example, threearticulated surgical tool instruments (TOOL1, TOOL2, TOOL3) 2231, 2241,2251 are used to robotically perform the procedure and an articulatedimaging system instrument (IS) 2261 is used to view the procedure. Inother examples, more or less instruments may be used. The imaging system2261 may be a stereoscopic camera instrument, such as camera instrument211, or another type of imaging system such as a monoscopic camerainstrument or an ultrasound probe instrument. The tools 2231, 2241, 2251and imaging system 2261 may be disposed in an entry guide (EG) 2000 soas to be extendable beyond a distal end of the entry guide 2000. Theentry guide 2000 may be inserted into the Patient through an entryaperture such as a minimally invasive incision or a natural orificeusing the setup portion of a robotic arm assembly and maneuvered by anentry guide manipulator (EGM) 2116 towards the work site where themedical procedure is to be performed.

Each of the devices 2231, 2241, 2251, 2261, 2000 is manipulated by itsown manipulator. In particular, the imaging system (IS) 2261 ismanipulated by an imaging system manipulator (PSM4) 2262, the firstsurgical tool (TOOL1) 2231 is manipulated by a first tool manipulator(PSM1) 2232, the second surgical tool (TOOL2) 2241 is manipulated by asecond tool manipulator (PSM2) 2242, the third surgical tool (TOOL3)2251 is manipulated by a third tool manipulator (PSM3) 2252, and theentry guide (EG) 2000 is manipulated by the entry guide manipulator(EGM) 2116.

Each of the instrument manipulators 2232, 2242, 2252, 2262 is amechanical assembly that carries actuators and provides a mechanical,sterile interface to transmit motion to its respective articulatedinstrument. Each of the articulated instruments 2231, 2241, 2251, 2261is a mechanical assembly that receives the motion from its manipulatorand, by means of a cable transmission, propagates the motion to itsdistal articulations (e.g., joints). Such joints may be prismatic (e.g.,linear motion) or rotational (e.g., they pivot about a mechanical axis).Furthermore, the instrument may have internal mechanical constraints(e.g., cables, gearing, cams, belts, etc.) that force multiple joints tomove together in a pre-determined fashion. Each set of mechanicallyconstrained joints implements a specific axis of motion, and constraintsmay be devised to pair rotational joints (e.g., joggle joints). Notealso that in this way the instrument may have more joints than theavailable actuators.

In direct control mode, each of the input devices 41, 42 may beselectively associated with one of the devices 2261, 2231, 2241, 2251,2000 through a multiplexer (MUX) 2290 so that the associated device maybe controlled by the input device through its controller andmanipulator. For example, the Surgeon may specify the associationthrough a graphical user interface (GUI) 2291 on the Surgeon console2102 for the left and right input devices 41, 42 to be respectivelyassociated with the first and second surgical tools 2231, 2241, whichare telerobotically controlled through their respective controllers2233, 2243 and manipulators 2232,2242 so that the Surgeon may perform amedical procedure on the Patient while the surgical tool 2251, imagingsystem 2261 and entry guide 2000 are each soft locked in place throughtheir respective controllers. If the Surgeon desires to control movementof the surgical tool 2251 using one of the input devices 41, 42, thenthe Surgeon may do so by simply disassociating the input device from itscurrently associated device and associating it instead to the tool 2251.Likewise, if the Surgeon desires to control movement of either theimaging system 2261 or entry guide 2000 using one or both of the inputdevices 41, 42, then the Surgeon may do so by simply disassociating theinput device from its currently associated device and associating itinstead to the imaging system 2261 or entry guide 2000.

As alternatives to using the GUI 2291 for providing selection input SELfor the MUX 2290, the selective association of the input devices 41, 42to devices 2251, 2241, 2231, 2261, 2000 may be performed by the Surgeonusing voice commands understood by a voice recognition system, or by theSurgeon depressing a button on one of the input devices 41, 42, or bythe Surgeon depressing a foot pedal on the Surgeon console 2102, or bythe Surgeon using any other well known mode switching technique.Although such mode switching is described herein as being performed bythe Surgeon, it may alternatively be performed by an Assistant under thedirection of the Surgeon.

Each of the controllers 2233, 2243, 2253, 2263, 2273 comprises amaster/slave control system that includes a joint controller for eachjoint of its respective articulated instrument or in the case of theentry guide 2000, its manipulator 2116. To simplify the descriptionherein and in the claims, the term “joint” is to be understood as aconnection (translational or revolute) between two links, and mayinclude gears (or prismatic joints) as well as any other controllablecomponent coupled to linear drive mechanisms that may be used incontrolling robotic arm assemblies. An example of such a control systemis described in previously incorporated by reference and U.S. Pat. No.6,424,885, “Camera Referenced Control in a Minimally Invasive SurgicalApparatus.”

Direct control modes are control modes in which the user has directcontrol over a specific slave manipulator. All other slave manipulators(i.e., the ones that are not connected to an input device) may besoft-locked (i.e., all their joints are held in place by theirrespective controllers). As an example, in a single-port system such asdescribed herein, three direct control modes are defined as a direct“tool following” mode in which the two hand-operable input devices areassociated with two tool slave manipulators and their respective tools,a direct “imaging system” mode in which one or both of the hand-operableinput devices are associated with the imaging system, and a direct“entry guide” mode in which one or both hand-operable input devices areassociated with the entry guide.

In a coupled control mode, the Surgeon is directly controlling movementof an associated slave manipulator (e.g., one of the manipulators 2232,2242, 2252, 2262, 2116) while indirectly controlling movement of one ormore non-associated slave manipulators, in response to commanded motionof the directly controlled slave manipulator, to achieve a secondaryobjective. By automatically performing secondary tasks through coupledcontrol modes, the system's usability is enhanced by reducing theSurgeon's need to switch to another direct mode to manually achieve thedesired secondary objective. Thus, coupled control modes allow theSurgeon to better focus on performing the medical procedure and to payless attention to managing the system.

The GUI 2291 used by the Surgeon to specify the association of inputsdevices 41, 42 and devices 2231,2241,2251,2261,2000 may also be used bythe Surgeon to specify various parameters of the coupled control modes.For example, the Surgeon may use the GUI 2291 to select which devicemanipulators participate in various coupled control modes and to defineand/or prioritize the secondary objectives associated with the coupledcontrol modes.

In “entry guide” mode, both input devices 41, 42 may be used to move theentry guide 2000 as the Surgeon views on the stereo viewer 45 processedimages that were originally captured by the camera 211. An imagereferenced control is implemented in the entry guide controller 2273 sothat the controller 2273 controls movement of the entry guide 2000 whilethe Surgeon is given the impression that he or she is moving the imagecaptured by the camera 211. In particular, the Surgeon is provided withthe sensation that he or she is grasping the image being displayed onthe viewer 45 with his or her left and right hands and moving the imageabout the work site to a desired viewing point. Note that under thiscontrol, the image on the viewer 45 appears to move in oppositedirections in response to movement of the input devices 41, 42. Forexample, the image moves to the right when the input devices 41, 42 moveto the left (and vice versa). Also, the image moves up when the inputdevices 41, 42 are moved down (and vice versa). Pivoting of the entryguide is accomplished using a “virtual handlebar” in which pivot pointsof the left and right input devices 41, 42 define a handle bar axiswhich passes through the pivot points. An entry guide yaw command maythen be generated by the Surgeon moving one input device forward whilemoving the other one back. An entry guide pitch command, on the otherhand, may be generated by the Surgeon pivoting both input devices aboutthe handle bar axis in the same direction (either up to pitch up or downto pitch down). An entry guide roll command may be generated by theSurgeon moving one input device up while moving the other input devicedown. An insertion command may be generated by the Surgeon moving bothinput devices backward and a retraction command may be generated by theSurgeon moving both input device forward.

When the Surgeon is operating in the “entry guide” mode to re-orient theentry guide 2000 along with all of the articulated instruments within itat the time, the Surgeon may inadvertently strike and harm the patient'sanatomy with an articulated instrument that is extending out of thedistal end of entry guide when the entry guide is being pivoted aboutits Remote Center (RC). For example, referring to FIG. 14, anarticulated instrument 1400 is shown in solid line form extending out ofthe distal end of the entry guide 2000 at an initial orientation andshown in dotted line form striking the patient anatomy 1410 after beingpivoted about the RC point. Although a distal end of the articulatedinstrument is shown as striking the patient anatomy in this example, inpractice, it is to be appreciated that other parts of an articulatedinstrument such as more proximal (i.e., closer to the entry guide) linksof the articulated instruments 211, 231, 241 may also potentially strikepatient anatomy due to the articulated nature of the instruments. Inaddition, it may be difficult for a Surgeon to foresee such strikingwhen viewing the work site on the stereo viewer 45 since the proximallinks may be out of the field of view of the camera instrument 211.Thus, to avoid inadvertently striking and harming the patient anatomy,it is advisable to retract all articulated instruments back into theentry guide before re-orienting the entry guide, such as shown, forexample, in FIG. 15, when large adjustments to the orientation of theentry guide 2000 are being made.

When there is a plurality of articulated instruments extending out ofthe entry guide 2000, such as shown in FIG. 7, it may be tedious andtime consuming for the Surgeon to change modes between “entry guide” and“tool following” modes, place the articulated instruments one-at-a-timeinto a retraction configuration (i.e., one in which the instrument maybe retracted into the entry guide) while changing associations betweenthe input devices and instruments as necessary, and retracting each ofthe articulated instruments after its reconfiguration into the entryguide 2000. Therefore, it would be useful to provide a coupled controlstructure in which the entry guide controller 2273 is coupled toinstrument controllers 2233, 2243, 2253, 2263 during “entry guide” modeso that the controllers 2233, 2243, 2253, 2263 automatically reconfigureand retract their respective articulated instruments upon receiving anindication to do so from the entry guide controller 2273.Reconfiguration and retraction of the articulated instruments may beperformed sequentially (or concurrently when safe to do so) in this caseeither under the control of the Surgeon or automatically by the systemwhile avoiding collisions among the instruments and with theirenvironment.

An example of such a coupled control structure is now described, whereinFIG. 16 illustrates a flow diagram including a method for re-orientingan entry guide having a plurality of extendable articulated instrumentsdisposed within it and FIG. 17 illustrates a coupled control structurewhich includes one or more coupling logic blocks for implementingaspects of the method of FIG. 16.

Referring to FIG. 16, in block 1601, the method receives an indicationthat the “entry guide” mode has been entered, as described, for example,in reference to FIG. 13. In block 1602, the method, in response tooperator commands to do so, concurrently retracts all articulatedinstruments extending out of the distal end of the entry guide back intothe entry guide either completely or at least to a point where theycannot harm the patient anatomy while the entry guide is being pivotedabout the Remote Center (RC) pivot point. FIGS. 18A-18C serve toillustrate general aspects of the retraction performed in block 1602.

In FIG. 18A, a top view of the entry guide 2000 is shown witharticulated instruments 231, 241, 211 extending out of its distal endsuch as shown in the perspective view of FIG. 7. In FIG. 18B, thearticulated instruments 231, 241, 211 are shown in their retractionconfigurations wherein their links line up so as to be retractable intoa corresponding lumen or space in the entry guide 2000. In FIG. 18C, thearticulated tool instruments 231, 241 are shown fully retracted into theentry guide 2000 while the articulated camera instrument 211 is shownonly partially retracted (or alternatively retracted so as to be justinside the entry guide) so that it may still capture a view out of thedistal end while not risking harm to the patient anatomy when the entryguide 2000 is being pivoted about the RC pivot point. Alternatively, thearticulated instruments 231, 241, 211 may not be fully retracted intothe entry guide 2000, but only enough so that none of them may harm (orbe placed in a position so as to cause unintended harm to) any patientanatomy when the entry guide 2000 is subsequently pivoted about theRemote Center (RC) to re-orient the entry guide 2000. Note that in thiscase, the articulated instruments 231, 241, 211 may be allowed to touchpatient anatomy as long as the touching does not result in harming thepatient anatomy.

Although the sequence shown in FIGS. 18A-18C suggests that thereconfiguration occurs before retraction starts, in practicing theinvention, the sequence of retraction and reconfiguration of theplurality of articulated instruments may be performed concurrently or ina different order depending upon certain conditions and the methodemployed.

As first method of the retraction and reconfiguration sequence, if themost proximal joint of the plurality of articulated instruments (e.g.joint 323 of the articulated camera instrument 211 in FIG. 18A) is at aminimum distance away from the distal end of the entry guide 2000, thenretraction may be allowed to occur concurrently with reconfigurationwith a straightening velocity that is proportional to the retractionvelocity (subject to maximum velocity limits). During reconfigurationand retraction, collisions between the reconfiguring and/or retractinginstruments should be predicted by the system and avoided, as well asavoiding harm to the patient anatomy. The velocity with which thearticulated instruments may be retracted and/or reconfigured ispreferably a function of how hard the Surgeon is pushing against anyhaptic feedback being provided on the controlling input device duringthe retraction and/or reconfiguration. If the most proximal joint (thatis not in the entry guide 2000 at the time) of the plurality ofarticulated instruments reaches the distal end of the entry guide 2000before its articulated instrument has been fully reconfigured to itsretraction configuration, then further retraction of the plurality ofarticulated instruments is prevented by the system until reconfigurationof the most proximal joint's articulated instrument into its retractionconfiguration has completed. This requirement is to avoid damage to thearticulated instrument and/or entry guide 2000. In this case, thevelocity for reconfiguration may still be a function of how hard theSurgeon is pushing against any haptic force being provided on thecontrolling input device, but possibly with a different gain. Theminimum distance from the distal end of the entry guide 2000 at whichconcurrent retraction and reconfiguration may occur may be determined byconsideration of several factors. One factor is the velocity at which intandem movement of the articulated instruments is being commanded (e.g.,the faster the commanded retraction movement, the larger the minimumdistance; and the faster the reconfiguration movement, the smaller theminimum distance). Another factor is the initial configurations of thearticulated instruments. For example, the closer the initialconfigurations of the plurality of articulated instruments are to theirretraction configurations, the shorter the minimum distance, and viceversa. Also, since it is undesirable for the distal ends of thearticulated instruments to extend forward beyond their initial positionsduring reconfiguration, because doing so may inadvertently harm thepatient anatomy, compensation for such extension is required in theretraction direction. Therefore, the amount of such extensioncompensation is still another factor in determining the minimumdistance.

As another and simpler method of the retraction and reconfigurationsequence, retraction may occur before reconfiguration. For example, theplurality of articulated instruments may be retracted in tandem until amost proximal joint (not already in the entry guide) of one of thearticulated instruments reaches the distal end of the entry guide 2000,whereupon further retraction is prohibited by the system andreconfiguration of the articulated instrument into its retractionconfiguration is initiated. Once reconfiguration for that articulationinstrument has completed, then the plurality of articulated instrumentsmay be retracted in tandem again until a most proximal joint (notalready in the entry guide) of one of the articulated instrumentsreaches the distal end of the entry guide 2000, whereupon furtherretraction is once again prohibited by the system and reconfiguration ofthat articulated instrument into its retraction configuration isinitiated if necessary. The above described sequence would then continueuntil all of the plurality of articulated instruments has been thusreconfigured and retracted into the entry guide 2000.

Referring back to FIG. 16, in block 1603, the method, in response tooperator commands to do so, pivots the entry guide 2000 about the RCpivot point to a new orientation. After completing the re-orientation ofthe entry guide 2000, in block 1604, the articulated instruments 231,241, 211 may then be re-inserted in response to operator commands to doso, and in block 1605, the operator may exit the “entry guide” mode andenter “tool following” mode so that the operator (e.g., Surgeon) mayperform or continue to perform a medical procedure on the patient withthe re-positioned entry guide 2000 and articulated instruments 231, 241,211.

FIG. 19 illustrates, as an example, a flow diagram of a method formoving a plurality of articulated instruments in tandem back towards anentry guide, which method may be implemented by the coupled controlstructure of FIG. 17 and used to perform the articulated instrumentretractions in block 1602 of FIG. 16.

In block 1901, the method receives information of a commanded change inthe position (q_(IO)) of the entry guide 2000 in a direction parallel tothe entry guide's insertion axis X′. The commanded position change inthis case is relative to the RC point, which serves as an initialposition from which the change in position is determined. In oneembodiment, the commanded position change (q_(IO)) may be made by theSurgeon commanding the entry guide 2000 to move along its insertion axisX′ when the system is in “entry guide” mode. In this case, however,instead of moving the entry guide 2000 along its insertion axis X′, allarticulated instruments extending out of the distal end of the entryguide 2000 are to be retracted back according to the commanded positionchange (q_(IO)).

In block 1902, the method makes a determination whether the commandedposition change (q_(IO)) is greater than a limit distance (IO_(LIM)). Ifthe determination is NO, then the method loops back to block 1901 toreceive information of another commanded position change (q_(IO)). Onthe other hand, if the determination in block 1902 is YES, then in block1903, the method causes a haptic force to be applied against a controlmechanism, which the operator uses to generate the commanded positionchange (q_(IO)), in a manner so as to progressively increase in force asthe position change commands along the insertion axis X′ generated bythe operator manipulating the control mechanism progressively exceed thelimit distance (IO_(LIM)), as depicted, for example, in the force versuscommanded position change (q_(IO)) function of FIG. 20. The controlmechanism in this case may include one or both of the input devices 41,42 of the Surgeon console 2102.

In block 1904, the method makes a determination whether the commandedposition change (q_(IO)) is greater than a locking distance (IO_(LOCK)),wherein the locking distance is greater than the limit distance. If thedetermination is NO, then the method loops back to block 1901 to receiveinformation of another commanded position change (q_(IO)). On the otherhand, if the determination in block 1904 is YES, then in block 1905, themethod causes pivot joints of the entry guide manipulator (EGM) 2116 tobe soft-locked in place using their respective joint controllers.

In block 1906, the method makes a determination whether the commandedposition change (q_(IO)) is greater than a retraction-on distance(IO_(ON)), wherein the retraction-on distance is greater than thelocking distance. If the determination is NO, then the method loops backto block 1901 to receive information of another commanded positionchange (q_(IO)). On the other hand, if the determination in block 1906is YES, then in block 1907, the method causes the arms (e.g., thecombination of joints and links) of the articulated instruments to bestraightened so as to be in proper retraction configurations whileconcurrently in block 1908, the retractions of the articulatedinstruments are subjected to a progressively increasing velocity limitby the method as the commanded position change (q_(IO)) progressivelyexceeds the retraction-on distance, as depicted, for example, in thevelocity versus commanded position change (q_(IO)) function of FIG. 21.

In block 1909, the method makes a determination whether the commandedposition change (q_(IO)) is greater than a maximum distance (IO_(MAX)),wherein the maximum distance is greater than the retraction-on distance.If the determination is NO, then the method loops back to block 1901 toreceive information of another commanded position change (q_(IO)). Onthe other hand, if the determination in block 1909 is YES, then in block1910, the retractions of the articulated instruments are subject to amaximum velocity limit (V_(MAX)) as the commanded position changesprogressively exceed the maximum distance, as depicted, for example, inthe velocity versus commanded position change (q_(IO)) function of FIG.21.

In block 1911, the method determines whether all articulated instrumentspreviously extending out of the distal end of the entry guide 2000 arenow in their retracted positions in the entry guide 2000. A retractedposition in this case does not necessarily mean that the instrument iscompletely retracted into the entry guide 2000. As shown in FIG. 18C,for example, the articulated camera instrument 211 may still have itsimage capturing end exposed out of the entry guide 2000 so that it mayget a better view of the surrounding area when the entry guide 2000 isbeing re-oriented by pivoting it about the RC point. This allows theSurgeon to view the portion of the patient anatomy where the entry guide2000 is being re-oriented towards. Other articulated instruments mayalso be only partially retracted as long as their extended portions donot strike and harm the patient anatomy during the entry guide 2000pivoting.

If the determination in block 1911 is NO, then the method loops back toblock 1901 to receive information of another commanded position change(q_(IO)). On the other hand, if the determination in block 1911 is YES,then in block 1912, the method causes pivot joints of the entry guidemanipulator (EGM) 2116 to no longer be soft-locked in place by theirrespective joint controllers. At this point, the entry guide 2000 may bere-oriented along with all articulated instruments disposed within itand the instruments may then be extended out of the entry guide 2000 soas to be positioned to perform or continue to perform a medicalprocedure on the patient.

Referring to FIG. 17, the methods described in reference to FIGS. 16 and19 may be implemented in one or more of an EG coupling logic 1700, PSM1coupling logic 1701, PSM2 coupling logic 1702, and PSM4 coupling logic1704 for the example in which articulated instruments 2231, 2241, 2261are disposed within the entry guide 2000. If more or less articulatedinstruments are extendable through the entry guide 2000, then thecoupling structure of FIG. 17 may be modified accordingly. Althoughshown as separate components, the coupling logic 1700, 1701, 1702, 1704may be structured as a single logic block by, for example, incorporatingall logic into the EG coupling logic 1700, or it may be structured in adistributed processing fashion by, for example, eliminating the EGcoupling logic 1700 and distributing the processing among the PSM1,PSM2, and PSM4 coupling logic 1701, 1702, 1704. Also, although shown asbeing separate from their respective controllers, each of the couplinglogic blocks may be integrated into their respective controllers such asthe EG coupling logic 1700 being integrated as part of the entry guidecontroller (CNTLG) 2273. Further, the processor 43 may implement allcontrol and coupling logic shown in FIG. 17 using computer program codestored in a memory unit of the system 2100. To simplify the drawing,block 2274 represents the combination of the entry guide manipulator2116 and entry guide 2000. Block 2264 represents the combination of theimaging system instrument manipulator 2262 and imaging system instrument2261. Block 2234 represents the combination of the tool instrumentmanipulator 2232 and tool instrument 2231. Block 2244 represents thecombination of the instrument manipulator 2242 and tool instrument 2241.

Although the moving of the articulated instruments 211, 231, 241 intandem back towards the entry guide 2000 is described above in referenceto re-orienting the entry guide 2000, it may also be useful to move aplurality of articulated instruments in tandem back towards the entryguide in other applications such as, for example, after the completionof a medical procedure. In these cases, rather than switching to the“entry guide” mode, the system may stay in an “imaging system” mode andmake use of coupled control logic such as illustrated in FIG. 22 to movethe articulated instruments 211, 231, 241 in tandem back towards theentry guide 2000. Likewise, the system may stay in a “tool following”mode and make use of coupled control logic such as illustrated in FIG.23 to move the articulated instruments 211, 231, 241 in tandem backtowards the entry guide 2000. In either case, the movement of thearticulated instruments in tandem back towards the entry guide 2000 isperformed in a similar manner as previously described with respect toFIGS. 19-21 with the exception that the pivot joints of the entry guide2000 do not need to be locked. This is because under both “imagingsystem” mode and “tool following” mode, the entry guide 2000 is alreadylocked in place (as illustrated, for example, in FIGS. 22, 23 by the“soft-locking” feedback from the entry guide and entry guide manipulatorcombination block 2274 to the entry guide controller 2273). Thus, FIGS.24-26 illustrate a method for moving a plurality of articulatedinstruments (e.g., 211, 231, 241) in tandem back towards the entry guide2000 that may be performed during “imaging system” and “tool following”modes, wherein FIG. 24 is performed substantially the same manner asdescribed in reference to FIG. 19 with the exception that blocks 1904,1905, 1912 related to locking the entry guide in place are deleted andFIGS. 25, 26 are respectively essentially the same as FIGS. 20, 21 withthe exception that the point IO_(LOCK) related to locking the entryguide in place has been deleted.

Although the various aspects of the present invention have beendescribed with respect to a preferred embodiment, it will be understoodthat the invention is entitled to full protection within the full scopeof the appended claims.

What is claimed is:
 1. A method for moving an articulated instrumentback towards an entry guide, out of which the articulated instrumentextends, with automatic reconfiguration of the articulated instrumentfor retraction into the entry guide, the method comprising: receiving,at a processor, information of a command, initiated from a controlmechanism, to change the position of the articulated instrument in adirection parallel to a longitudinal axis of the entry guide;determining, by the processor, whether the information of the commandindicates the position of the articulated instrument is to be moved backtowards the entry guide by a distance greater than a retraction-ondistance in the direction parallel to the longitudinal axis of the entryguide relative to an initial position; and on the condition that theinformation of the command indicates the position of the articulatedinstrument is to be moved back towards the entry guide by the distancegreater than the retraction-on distance from the initial position,automatically commanding, by the processor, the articulated instrumentto be reconfigured towards a retraction configuration suitable forentering the entry guide while the position of the articulatedinstrument is being changed in response to the command initiated fromthe control mechanism.
 2. The method of claim 1, further comprising: onthe condition that the information of the command indicates the distalend of the articulated instrument is to be moved back towards the entryguide by the distance greater than the retraction-on distance from theinitial position, automatically commanding, by the processor, an abruptchange to a haptic force applied against the control mechanism.
 3. Themethod of claim 1, further comprising: receiving, at the processor,information of a sequence of commands, initiated from the controlmechanism, to change the position of the articulated instrument in thedirection parallel to the longitudinal axis of the entry guide;determining, by the processor, whether the information of the sequenceof commands from the control mechanism indicates the distal end of thearticulated instrument is to be moved back towards the entry guide bydistances which progressively exceed a limit distance from the initialposition, wherein the limit distance is less than the retraction-ondistance; and on the condition that the information of the sequence ofcommands from the control mechanism indicates the distal end of thearticulated instrument is to be moved back towards the entry guide bydistances which progressively exceed a limit distance from the initialposition, automatically commanding, by the processor, a progressivelyincreasing haptic force applied against the control mechanism inresponse to the sequence of commands from the control mechanism.
 4. Themethod of claim 3, further comprising: on the condition that theinformation of the command indicates the position of the articulatedinstrument is to be moved back towards the entry guide by the distancegreater than the retraction-on distance from the initial position,automatically commanding, by the processor, movement of the articulatedinstrument to be subject to a progressively increasing velocity limit asthe sequence of commands indicate the articulated instrument is to bemoved back towards the entry guide by distances which progressivelyexceed the retraction-on distance from the initial position.
 5. Themethod of claim 3, further comprising: determining, by the processor,whether one command of the sequence of commands indicates thearticulated instrument is to be moved back towards the entry guide by adistance that exceeds a maximum velocity distance from the initialposition, wherein the maximum velocity distance is greater than theretraction-on distance; and on the condition that the information of thesequence of commands indicates the articulated instrument is to be movedback towards the entry guide by the distance that exceeds the maximumvelocity distance from the initial position, automatically commanding,by the processor, the articulated instrument to be moved in a mannerwhich is subject to a maximum velocity limit.
 6. A robotic systemcomprising: a control mechanism; an entry guide; an articulatedinstrument extending out of a distal end of the entry guide; aninstrument manipulator configured to manipulate the articulatedinstrument; and a processor programmed to: receive information of acommand, initiated from the control mechanism, to change a position ofthe articulated instrument in a direction parallel to a longitudinalaxis of the entry guide; determine whether the information of thecommand indicates the position of the articulated instrument is to bemoved back towards the entry guide by a distance greater than aretraction-on distance in the direction parallel to the longitudinalaxis of the entry guide relative to an initial position; and on thecondition that the information of the command indicates the position ofthe articulated instrument is to be moved back towards the entry guideby the distance greater than the retraction-on distance from the initialposition, automatically command the instrument manipulator toreconfigure the articulated instrument towards a retractionconfiguration suitable for entering the entry guide while the positionof the articulated instrument is being changed in response to thecommand initiated from the control mechanism.
 7. The system of claim 6,wherein the processor is programmed to: cause an abrupt change to ahaptic force being applied against the control mechanism upon thecommand initiated from the control mechanism indicating the articulatedinstrument is to be moved back towards the entry guide by the distancegreater than the retraction-on distance from the initial position. 8.The system of claim 6, wherein the processor is programmed to: cause aprogressively increasing haptic force to be applied against the controlmechanism in response to a sequence of commands from the controlmechanism to move the articulated instrument back towards the entryguide by distances which progressively exceed a limit distance from theinitial position, wherein the limit distance is less than theretraction-on distance, and wherein the progressively increasing hapticforce, the sequence of commands, and the distances which progressivelyexceed a limit distance correspond.
 9. The system of claim 8, whereinthe processor is programmed to: on the condition that the information ofthe command indicates the position of the articulated instrument is tobe moved back towards the entry guide by the distance greater than theretraction-on distance from the initial position, automatically commandthe instrument manipulator to move the articulated instrument so as tobe subject to a progressively increasing velocity limit as the sequenceof commands correspondingly indicate the articulated instrument is to bemoved back towards the entry guide by distances which progressivelyexceed the retraction-on distance from the initial position.
 10. Thesystem of claim 8, wherein the processor is programmed to: determinewhether one of the sequence of commands indicates the articulatedinstrument is to be moved back towards the entry guide by a distancethat exceeds a maximum velocity distance from the initial position,wherein the maximum velocity distance is greater than the retraction-ondistance; and on the condition that the information of the sequence ofcommands indicates the articulated instrument is to be moved backtowards the entry guide by the distance that exceeds the maximumvelocity distance from the initial position, automatically command theinstrument manipulator to move the articulated instrument in a mannerwhich is subject to a maximum velocity limit.